<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box {
      width: 100px;
      height: 100px;
      background-color: pink;
    }
  </style>
  <script src="../js/jquery.min.js"></script>
  <script>
    $(() => {
      $('div').hide()
      console.log($('div'))
      //jq对象转成dom对象
      console.log($('div')[0])
      console.log($('div').get(0))
      //dom对象转jq对象
      const mydiv = document.querySelector('div')
      console.log($(mydiv))
    })
  </script>
</head>

<body>
  <div class="box"></div>
</body>

</html>